1. Technical Field
The present disclosure relates to a reflective liquid-crystal display device and an electronic apparatus including the same.
2. Description of the Related Art
There have been developed some types of display devices, including transmissive display devices and reflective display devices. Transmissive display devices perform display using transmitted light of backlight output from the back surface of a screen. Reflective display devices perform display using reflected light of external light. Reflective display devices have characteristics in that less power consumption is required and that the screen is easy to see under a bright environment.
Some reflective display devices are provided with a front light unit that makes light incident from a video display surface side so as to make the reflective display devices available in a place with no or less external light (refer to Japanese Patent Application Laid-open Publication No. 2004-6128 (JP-A-2004-6128) and Japanese Patent Application Laid-open Publication No. 2001-345008 (JP-A-2001-345008)). JP-A-2004-6128, for example, discloses a front lighting system. The front lighting system is provided with a light guide including an incident unit on which light is incident from a light source and a reflecting unit that reflects the light output from the light source toward an object to be illuminated. The front lighting system is used in a manner arranged in front of the object to be illuminated. The front lighting system is further provided with a diffusion unit that diffuses the reflected light received from the reflecting unit between the incident unit and the reflecting unit.
By arranging such a front light unit on the side of a liquid-crystal display panel that displays an image, that is, on the display surface side, making light incident on the liquid-crystal display panel from the front light unit, and reflecting the light by using a reflective electrode, a reflective liquid-crystal display device can output light from the display surface when external light is insufficient. Because the light can be incident in the same direction as in the case where external light is used, it is possible to use the light efficiently.
The front light unit includes a light source and a light guide plate. The light guide plate is laminated on the display surface of the liquid-crystal display panel to scatter and reflect light output from the light source, thereby making the light incident on the liquid-crystal display panel, for example. Some light guide plates have recesses and protrusions formed on a surface parallel to the display surface to make light entering from the light source arranged on the side surface and traveling along the display surface incident on the liquid-crystal display panel. In recent years, fine recesses and protrusions can be formed on the surface to further average the light output from the light source and reflect the light to the liquid-crystal display panel, thereby improving the optical characteristics. However, if the reflective liquid-crystal display device is provided with a front light unit including a light guide plate having fine recesses formed on its surface, moire may possibly occur in a displayed image.
For the foregoing reasons, there is a need for a need for a reflective liquid-crystal display device that can suppress moire and an electronic apparatus including the same.